Window frame construction having a folded mitered corner



Feb. 28, 1967 R. J. DEISENROTH 3,305,998

WINDOW FRAME CONSTRUCTION HAVING A FOLDED MITERED CORNER Filed July 17, 1964 INVENTOR.

Ross/2r J DEISENROTH BY $26 5 ML 01v, San-LE z Clan/e QTTQENEYS United States Patent ()fiice 3,305,998 Patented Feb. 28, 1967 3,305,998 WINDOW FRAME CONSTRUCTION HAVING A FOLDED MITERED CORNER Robert J. Deisenroth, Elkhart, Ind, assignor to Excel Corporation, Elkhart, Ind, a corporation of Indiana Filed July 17, 1964, Ser. No. 383,337 6 Claims. (Cl. 52656) The present invention relates to a metallic window frame construction, and more particularly to a window frame construction having a folded mitered corner,

Window frames, such as the type used in school buses to receive a slidable sash, are conventionally made from a length of metallic channel. Spaced apart pairs of V-shaped notches are provided in the legs of the channel at the points where the channel is to be bent to form a corner of the frame. The V-shaped notches extend from the outer edges of the channel legs and terminate at the web which interconnects the legs. The channel web is bent along a line defined by two opposing V-shaped notches to form a mitered corner. This results in a corner which is relatively weak because of the high stress placed on the channel web at the point of bending. Frequently, a crack develops along this line resulting in eventual failure of the window frame at the corner.

The present invention solves this problem by providing a mitered corner in which material of the channel legs is present at the corner and is deformed when the channel is bent to form the corner to result in a construction of very high strength.

It is therefore an object of the invention to provide a window frame constructed of a single length of metallic channel wherein the channel is bent to form folded mitered corners in which material of the channel legs as well as material of the channel Web is present at the point of bend.

Another object of the invention is to provide a window frame construction in which a channel is initially provided with pairs of opposing notches in the channel legs at the points where the corners are to be formed, each notch extending from the outer edge of channel legs and terminating short of the web which interconnects the channel legs.

A-further object of the invention is to provide a method for bending the channel wherein the material in the channel legs between the notch and the channel web is required to fold inwardly of the channel during the bending process to avoid the presence of projections on the exterior of the window frame.

A still further object of the invention is to provide a window frame construction wherein the outer corner surfaces have a curved configuration rather than the usual right angle shape.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters design-ate corresponding parts in the several views.

In the drawing:

FIGURE 1 is a perspective view of a channel member prior to bending to form a window frame in accordance with one embodiment of the present invention;

FIGURE 2 is a sectional view illustrating the method and apparatus for bending the channel of FIGURE 1;

FIGURE 3 is a sectional view taken substantially along the line 33 of FIGURE 2 looking in the direction of the arrows;

FIGURE 4 is a front elevational view of a finished window frame construction, and

FIGURE 5 is an enlarged view of a corner section of the finished window frame of FIGURE 4.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phaseology or terminology employed herein is for the purpose of description and not of limitation.

FIGURE 1 illustrates a metallic channel member 10 prior to bending to form the finished window frame 12 of FIGURE 4. The elongated channel member 10 comprises a pair of spaced apart legs 14, 16 interconnected by a web 18. Inwardly extending lips 20, 22 are formed on the outer edges of the legs 14, 16 to retain the usual glass run member which serves as a Weather strip and as a mounting for the slidable window sash.

Two pairs of spaced apart opposing notches 24, 26, 28, 30 are provided in the legs 14, 16. The notches delineate the left and right jam'bs 32, 34 and interconnecting header 36 of the window frame 12.

Each notch is defined by a pair of side edges 38, 40 which extend from the outer edges of the legs 14, 16 and converge towards the channel web 18. The side edges 38, 40 terminate short of the web 18 and are connected by bottom edge 42. Bottom edge 42 is parallel to the Web 18. The notch side edges 38, 40 are preferably angled so that if they were continued they would intersect at the Web 18 to form the usual V-shaped notch used to form mitered corners. However, termination of the edges 38, 40 short of the web 18 results in leaving a portion 44 of the channel side wall between the notch and the web 18. The edges 38, 40 of the notches are each at an angle of 45 with respect to the plane of the web 18 as is conventional in forming a right-angle corner. The notches 24, 26, 28, 30 may be defined as having a trapezoidal geometrical shape formed by truncating an equilaterial triangle.

The method of forming the frame 12 from the channel 10 is illustrated in FIGURES 2 and 3. A female die member 46 is provided with an elongated channel 48 to receive the channel member 10. The channel member 10 seats on the bottom surface 50. A right-angle recess 52 extends downwardly from the surface 50. The channel 10 is seated on the surface 50 with a pair of notches, illustratively notches 24, 26, positioned directly over the bottom center 54 of the recess 52. It will be noted that the bottom 54 is rounded.

A male die member 56 is positioned over the center 54 of the recess 52. The male die 56 may be suitably mounted in power machinery (not shown) for downward movement into the channel 10 to force this member into the recess 52 for bending into the desired corner shape. As will be noted, the lower end 58 of the die member 56 is rounded to conform to the rounded portion '54 of the recess 52. A small cavity 60, 62 is provided on each side of the die member 56 adjacent the lower end 58. The cavities 60, 62 function to receive folded-in portions of the channel legs 14, 16 during the bending step.

After the channel 10 has been placed in the female die member 46 as shown in full lines in FIGURE 2, the male die member 56 is moved downwardly and enters the channel 10. Upon contacting the web 18, the die 56 forces the channel 10 into the recess 52 causing the channel 10 to deform to the position illustrated in dotted lines. The edges 38, 40 of the notches meet as illustrated in FIGURE 5. The outer corner surface 64 is stretched to conform to the shape of the end 58 of the male die and portion 54 of the recess 52 of the female die to the rounded contour illustrated. This rounded contour has two desirable aspects. Firstly, bending and stretching the web 18 to form a rounded contour rather than bending this member along a single line to form a sharp rightangle corner divides the stress on the corner evenly over the entire area of the corner rather than concentrating the stress on a single line. Additionally, the rounder corner provides a clearance at the corner when the window is set into a square window opening. This clearance allows for weld beads which are present at the window opening corners. These weld beads result from the method of construction of the vehicle body.

As best illustrated in FIGURE 3, the material 44 between the notches and the web 18 is formed inwardly during the forming process to form inwardly extending dimples 66, 68. The material 44 is urged inwardly rather than outwardly as a result of the construction of the die members 46, 56. The recess 52 of the female die member 46 is substantially equal in width to the overall width of the channel 10. Consequently, when a force is exerted by the male die member 56 to bend the channel It the material 44 cannot fold outwardly but must fold inwardly into the cavities 60, 62 of the die member 56. It is advantageous to have the dimples 66, 68 projected inwardly rather than outwardly both from the standpoint of appearance and to eliminate relatively sharp exterior projections on the finished window frame 12. As previously mentioned, the presence of the material 44 at the corner serves to provide reinforcing material at the corner resulting in a sound, strong corner construction.

Having thus described my invention, I claim:

1. In a window frame constructed of a channel member having a pair of side walls interconnected by a web, a corner construction comprising two frame members joined by a corner portion with the channel web forming the outer corner surface and the channel side walls extending inwardly therefrom towards the center of the frame, each corner portion of the channel side walls having a slit therein extending from the inner edge thereof towards the web and terminating at a point short of the web, the channel side wall material between the termination of the slits and the web being folded inwardly of the channel.

2. In a window frame constructed of a channel member having a pair of side walls interconnected by a web, a corner construction comprising two frame members joined by a corner portion with the channel web forming the outer corner surface and the channel side walls extending inwardly therefrom towards the center of the frame, the web corner portion being configured as a smooth curve extending between the frame members, each corner portion of the channel side walls having a slit therein extending from the inner edge thereof towards the web and terminating at a point short of the web, the channel side wall material between the termination of the slits and the web being folded inwardly of the channel.

3. A window frame constructed of a continuous channel member having a pair of side walls interconnected by a web, the web forming the outermost surface of the frame with the channel side walls extending inwardly therefrom towards the center of the frame, said frame comprising a pair of substantially parallel right and left jambs interconnected by a header, the jambs being connected to the header by a corner portion, each corner portion of the channel side walls having a slit thereinextending from the inner edge thereof towards the web side wall material between the termination of the slits and the web being folded inwardly of the channel.

4. A window frame constructed of a continuous channel member having a pair of side walls interconnected by a web, the web forming the outermost surface of the frame with the channel side walls extending inwardly therefrom towards the center of the frame, said frame comprising a pair of substantially parallel right and left jambs interconnected by a header, the jambs being connected to the header by a corner portion, the web cor ner portion being configured as a smooth curve extending between the frame members, each corner portion of the channel side walls having a slit therein extending from the inner edge thereof towards the web and terminating at a point short of the web, the channel side wall material between the termination of the slits and the web being folded inwardly of the channel.

5. A channel member including spaced apart side walls interconneced by a web for forming into a window frame, said channel member having at least one set of oppositely disposed notches in the side walls located at a point along the channel for subsequent deformation of the channel to form a corner of the frame, each notch comprising first and second converging edges extending from the outer edge of the channel side wall toward the web, said converging edges terminating short of the web, and a third edge extending between the termination points of the first and second edges.

6. A channel member including spaced apart side walls interconnected by a web for forming into a window frame, said channel member having at least one set of oppositely disposed notches in the side walls located at a point along the channel for subsequent deformation of the channel to form a corner of the frame, each notch comprising first and second converging edges extending from the outer edge of the channel side wall toward the web, said first and second edges each being at an angle of substantially 45 with respect to the plane of the web and positioned with respect to each other to theoretically intersect at the web, said first and second edges terminating short of the web, and a third edge extending between the termination point of the first and second edges.

References Cited by the Examiner UNITED STATES PATENTS 1,615,823 2/1927 Barclay 189-76 1,836,354 12/1931 Abrams 29476 1,854,144 4/1932 Shrosbree et al. 52656 2,219,593 10/1940 Lang 189-75 2,219,594 10/1940 Lang 18975 2,219,595 10/1940 Lang 29476 2,781,111 2/1957 Kunkel 18975 2,831,244 4/1958 Adell 29-476 2,847,731 8/1958 Hollander 52-658 2,954,342 9/1960 Schnittker 52658 3,074,772 1/1963 Kessler et al. 52658 X FOREIGN PATENTS 380,259 9/1932 Great Britain.

HARRISON R. MOSELEY, Primary Examiner, A. I. BREIER, Assistant Examiner, 

1. IN A WINDOW FRAME CONSTRUCTED OF A CHANNEL MEMBER HAVING A PAIR OF SIDE WALLS INTERCONNECTED BY A WEB, A CORNER CONSTRUCTION COMPRISING TWO FRAME MEMBERS JOINED BY A CORNER PORTION WITH THE CHANNEL WEB FORMING THE OUTER CORNER SURFACE AND THE CHANNEL SIDE WALLS EXTENDING INWARDLY THEREFROM TOWARDS THE CENTER OF THE FRAME, EACH CORNER PORTION OF THE CHANNEL SIDE WALLS HAVING A SLIT THEREIN EXTENDING FROM THE INNER EDGE THEREOF TOWARDS THE WEB AND TERMINATING AT A POINT SHORT OF THE WEB, THE CHANNEL SIDE WALL MATERIAL BETWEEN THE TERMINATION OF THE SLITS AND THE WEB BEING FOLDED INWARDLY OF THE CHANNEL. 